With all my windows closed, why don't I suffocate?

Factual Questions
1

A few nights ago, it was warm enough for me to leave my windows open overnight for one of the first times this year. As I lay in bed drifting to sleep, enjoying deep breaths of cool, fresh air, I wondered: why do I not need to do this in winter? How is it that I can remain shut in my apartment for hours at a time, with the door and all the windows closed, and not run out of oxygen? I know ordinary doors and windows aren’t perfectly airtight, but still… do reasonably well-insulated doors and windows (as mine appear to be) let in air at a greater rate than a normal adult male consumes it?

2

Part of it is the flow of air through cracks, etc. You also open your door (I assume) periodically, which exchanges some air. Another factor is your heating system. Furnaces pull in fresh air in order to run. If you have forced air, it pulls in even more fresh air. Even if your heat consists solely of electrical baseboard heaters, they help contribute to the circulation of air through convection.

3

Well, if you close all the windows and run a fan, then you’ll die.

At least, when I was stationed in Korea, this was one of those urban legends the locals told me. I’m sure they don’t really believe it, it’s probably similar to some of our semi-wacky ‘old wives tales’.

4

Tedster, Cecil did a column about that. Will sleeping in a closed room with an electric fan cause death?

5

If you have plants, don’t forget they’re helpfully changing the carbon dioxide you exhale into yummy oxygen for you to inhale. (If I remember my grade school biology right, which isn’t likely.)

6

Interesting question: my WAG.

  1. A room would have to be well-constructed and well-insulated for you to suffocate.

  2. A room that is that well constructed is likely to be well designed, due to first world building codes. And liability standards.

Thank the government (all 3 branches).

You do not suffocate in your car for similar reasons.

7

The average person would breathe about 5 L of air/minute while sleeping. Lets say a small room 5m x 5m x 3m which is a volume of 75,000 litres. Thus the room will keep you alive for at least 15,000 minutes or 250 hours. I don’t think that you will have to worry about suffocating overnight [very approximate calculations - the increase in CO2 would probably kill you before the lack of O2?]